Between 13 million and 18 million people have been stricken with the flu as of Jan. 11, according to the latest CDC data.
Flu activity so far
According to Friday's Weekly Influenza Surveillance report from CDC, 48 states were experiencing widespread flu activity in the week ending in Jan. 11. Meanwhile, Oregon was experiencing regional flu activity, and Washington, D.C. and Hawaii were experiencing local flu activity.
By some indicators, this season so far is worse than last. For example, the data shows the cumulative hospitalization rate for the flu is 19.9 per 100,000 people this season, compared with 14.1 per 100,000 at the same point last season.
Eric Nakkim, co-medical director of Torrance Memorial Medical Center's ED, said his hospital has increased ED staffing levels and opened extra treatment areas to deal with the influx of flu patients. "We've already seen more flu patients this season than we did all of last season," he said.
According to CDC, this year's flu season has led to at least 5.9 million medical visits and 120,000 hospitalizations. The data also shows that between 6,600 and 17,000 flu-related deaths occurred from Oct. 1, 2019, to Jan. 11. In addition, while CDC found that the percentage of outpatient visits for influenza-like illness decreased to 4.7% in the week ending Jan. 11, that figure remains above the national baseline of 2.4%.
Children, young people hit hard by flu season
This flu season has been especially bad for children, according to CDC. The latest CDC report shows 39 pediatric deaths have been reported as of Jan. 11.
According to the Washington Post, the influenza B strain, which is more likely to cause complications in children and younger adults, is dominating in most areas of the country—and there's a subgroup of the B strain going around that is not included in this year's flu vaccine. However, CDC officials said the two types of influenza B are similar, so the vaccine should still be useful. "They are close enough so the vaccine offers some protection," according to Lynnette Brammer, head of CDC's domestic influenza surveillance team.
Jeffrey Gunzenhauser, CMO for Los Angeles County's public health department, said this year's flu season has been "unusual" because, "[w]hile a lot of people are sick, it's mostly affecting young people … It looks like older people are protected."
Experts are unsure why influenza B is more likely to affect younger people, the Los Angeles Times reports. Some believe that older people may have some immunity to influenza B, as it doesn't mutate as much as other flu strains do, meaning it's possible older people have caught the flu circulating this season before (CDC Weekly U.S. Influenza Surveillance Report, 1/10; CDC "Flu View," accessed 1/13; CDC Preliminary In-Season 2019-2020 Flu Burden Estimates, accessed 1/13; Cohen/Bonifield, CNN, 1/6; Sun, Washington Post, 1/10; Karlamangla, Los Angeles Times, 1/17).